Field of Invention
This invention relates to thermo-electric technology, and more particularly to a thin-film thermo-electric generator and fabrication method thereof.
Description of Related Arts
The thermo-electric generator is a kind of generator made on the basis of Seebeck Effect, the heat energy is transformed into electric energy. The working principle of thermo-electric generator is that connecting one end of two different metals or two different types of thermo-electric conversion materials P-type and N-type semiconductors, placing this end in high temperature condition, and placing the other end in low temperature condition. Compared with the other end, the end in high temperature condition has better thermal activation and higher density of electrons and holes, the electrons and holes spread to the end in low temperature condition, thus an electric potential difference is formed in the end in low temperature condition. Combing a number of this kind of thermo-electric conversion materials P-type and N-type semiconductors to form a module supplying adequate voltage, this module becomes a thermo-electric generator.
The thermo-electric generator is a kind of clean, noiseless energy without discharging any hazardous substance, having high reliability and long useful time, and supplying long, safe, continuous and stable electricity output. Presently the thermo-electric generator is made by cutting and welding the thermo-electric materials. There are two types of fabrication methods. In the first method, depositing a photosensitive resist on the same chip, then forming a P-type and N-type area through double photo etching respectively, and finally depositing P-type and N-type thermo-electric materials in the P-type and N-type area respectively. This method is difficult for application, especially for the procedure of combining thermo-electric units in which the chip is required to be stripped from the deposited thermo-electric units. In the second method, P-type and N-type thermo-electric unit chip is separately manufactured, in the fabrication of micro thin-film thermo-electric generator, the conducting layer connecting P-type and N-type thermo-electric units can be manufactured on condition that the chip is not stripped from the deposited thermo-electric units. This method has complicated procedures, and the thin-film of the thermo-electric generator is merely limited to single thin-film, so the performance is limited.